This description relates to identifying stopping places for an autonomous vehicle.
As shown in FIG. 1, a typical activity of an autonomous vehicle (AV) 10 is to safely and reliably drive through a road environment 12 to a goal position 14, while avoiding vehicles, pedestrians, cyclists and other obstacles 16 and obeying the rules of the road. We sometimes refer to the AV's ability to perform this activity as an “autonomous driving capability”.
The autonomous driving capability of an AV typically is supported by an array of technology 18, 20 including hardware, software, and stored and real time data that we together sometimes refer to as an AV system 22. Some or all of the technology is onboard the AV and some of the technology may be at a server, for example, in the cloud. Most AV systems include some or all of the following basic components:
1. Sensors 24 able to measure or infer or both properties of the AV's state and condition, such as the vehicle's position, linear and angular velocity and acceleration, and heading (i.e., orientation of the leading end of the AV). Such sensors include but are not limited to, e.g., GPS, inertial measurement units that measure both vehicle linear accelerations and angular rates, individual wheel speed sensors and derived estimates of individual wheel slip ratios, individual wheel brake pressure or braking torque sensors, engine torque or individual wheel torque sensors, and steering wheel angle and angular rate sensors.
2. Sensors 26 able to measure properties of the vehicle's surroundings. Such sensors include but are not limited to, e.g., LIDAR, RADAR, monocular or stereo video cameras in the visible light, infrared, or thermal spectra, ultrasonic sensors, time-of-flight (TOF) depth sensors, as well as temperature and rain sensors.
3. Devices 28 able to communicate the measured or inferred or both properties of other vehicles' states and conditions, such as other vehicles' positions, linear and angular velocities, and accelerations, and headings. These devices include Vehicle-to-Vehicle (V2) and Vehicle-to-Infrastructure (V2I) communication devices, and devices for wireless communications over point-to-point or ad-hoc networks or both. The devices can operate across the electromagnetic spectrum (including radio and optical communications) or other media (e.g., acoustic communications).
4. Data sources 30 providing historical, real-time, or predictive information or combinations of them about the local environment, including traffic congestion updates and weather conditions. Such data may be stored on a memory storage unit 32 on the vehicle or transmitted to the vehicle by wireless communication from a remotely located database 34.
5. Data sources 36 providing digital road map data drawn from GIS databases, potentially including high-precision maps of the roadway geometric properties, maps describing road network connectivity properties, maps describing roadway physical properties (such as the number of vehicular and cyclist travel lanes, lane width, lane traffic direction, lane marker type and location), and maps describing the spatial locations of road features such as crosswalks, traffic signs of various types (e.g., stop, yield), and traffic signals of various types (e.g., red-yellow-green indicators, flashing yellow or red indicators, right or left turn arrows). Such data may be stored on a memory storage unit on the AV or transmitted to the AV by wireless communication from a remotely located database.
6. Data sources 38 providing historical information about driving properties (e.g., typical speed and acceleration profiles) of vehicles that have previously traveled along the local road section at a similar time of day. Such data may be stored on a memory storage unit on the AV or transmitted to the AV by wireless communication from a remotely located database.
7. A computer system 40 located on the AV that is capable of executing algorithms (e.g., processes 42) for the on-line (that is, real-time on board) generation of control actions based on both real-time sensor data and prior information, allowing an AV to execute its autonomous driving capability.
8. A display device 44 that is connected to the computer system to provide information and alerts of various types to occupants of the AV.
9. A wireless communication device 46 to transmit data from a remotely located database 34 to the AV and to transmit vehicle sensor data or data related to driver performance to a remotely located database 34.
10. Functional devices and features 48 of the AV that are instrumented to receive and act on commands for driving (e.g., steering, acceleration, deceleration, gear selection) and for auxiliary functions (e.g., turn indicator activation) from the computer system.
11. A memory 32.